Last summer my mom found a HUGE flush of jack o lantern
mushrooms growing on a stump in the woods beside the road. She picked some just because they were so beautiful (like giant orange chanterelles) and wanted to ID them and then we found out they are BIOLUMINESCENT! ...but only when alive. We went back at night to check them out and boy was it cool. They didn't glow brightly like the ones in that picture, though... and they glowed blue, not green. (FYI they are toxic.)